Electrical conductivity (EC) of milk is an indicator of mastitis, and could, if it shows genetic variation and is genetically correlated to mastitis, be used in a breeding program where selection for reduced mastitis resistance is included. In this study, daily measurements of EC and mastitis were analyzed with a bivariate model. For EC, the estimated heritability was high (0.22 to 0.39), while...

the objective of the present study was to estimate heritability values for some performance and egg quality traits of native fowl in isfahan breeding center using reml and bayesian approaches. the records were about 51521 and 975 for performance and egg quality traits, respectively. at the first step, variance components were estimated for body weight at hatch (bw0), body weight at 8 weeks of a...

adjusted milk yield for 305 days and two milking times along with actual first lactation records of 187138 holstein cows were used to find out the effect of record adjustment on variance components estimation and on genetic evaluation. records had been gathered by the animal breeding center of iran during years 1991 to 2006. the pedigree file included 288032 animals. a single animal model with ...

The objective of this study was to estimate the genetic parameters of milk protein yields in Iranian Holstein dairy cattle. A total of 1,112,082 test-day milk protein yield records of 167,269 first lactation Holstein cows, calved from 1990 to 2010, were analyzed. Estimates of the variance components, heritability, and genetic correlations for milk protein yields were obtained using a random reg...

Milk yield records from 1st to 5th lactations of Iranian Holstein cows were analyzed using repeatability and a number of multivariate models that varied in additive genetic variance structure. A total of313,006 milk yield records were used. The records were obtained from 116,531 cows born between 2001 and 2005. The animals originated from 2,355 sires and 91,212 dams. A multivariate model with h...

The objective of the present study was to estimate heritability values for some performance and egg quality traits of native fowl in Isfahan breeding center using REML and Bayesian approaches. The records were about 51521 and 975 for performance and egg quality traits, respectively. At the first step, variance components were estimated for body weight at hatch (BW0), body weight at 8 weeks of a...

the aim of this study was to estimate the genetic and phonotypic trends of somatic cell score in iranian holstein cows. also, the environmental factors affecting this trait are investigated. a total of 375351 test day records of somatic cells take from 54374 animals between year 2002 and 2007 were used in this study. the breeding values were estimated by fitting animal model in asreml software....

Purebred Holstein-Friesian cows are the main exotic breed used for milk production on large, medium, and small farms in Kenya. A study was undertaken on seven large-scale farms to investigate the genetic trends for milk production and fertility traits between 1986 and 1997 and the genetic relationships between the traits. This involved 3,185 records from 1,614 cows, the daughters of 253 sires. ...